An Integrated Reactive Separation Process for Co-Hydrotreating of Vegetable Oils and Gasoil to Produce Jet Diesel

Abstract An integrated reactive separation process for the production of jet diesel from vegetable oils and gasoil mixture has been developed. The integrated reactive separation process consider three interconnected sections: 1) a triglyceride hydrolysis section consisting of a catalytic heterogeneous reactor which is used to transform the triglycerides of the vegetable oils or animal fats to the corresponding fatty acids and a coupled decanter-distillation column to separate the fatty acids from glycerol and water; 2) a co-hydrotreating section where a reactive distillation column is proposed to perform the deep hydrodesulfurization (HDS) of gasoil and the hydrodeoxigenation (HDO) and the decarbonilation of the fatty acids simultaneously and 3) a isomerization section where a catalytic reactor is used to produce the jet diesel with the appropriate fuel properties. Through intensive simulations the effect of the different operating variables of the three sections were studied. Results show that for the first section the water excess and the operating pressure are key variables for the transformation of the triglycerides. For the reactive distillation column for the HDS of gasoil and HDO of the fatty acids, it is very important to maintain the hydrogen excess in the feed with a low reflux ratio to allow the release of the light gases produced and, to guarantee the deep HDS of gasoil and the complete transformation of the vegetable oils. Finally, the isomerization reactor must be carefully operated with respect to the amount of light hydrocarbons compounds allowed in the mixture to be cracked and isomerized.